1. Field
The disclosure relates to an internal combustion engine having an intake valve and an exhaust valve.
2. Description of Related Art
In a cylinder head of an internal combustion engine, a valve seat, which a head of a valve contacts, is provided in a connecting part in which an intake port is connected with a combustion chamber. Also, in a connecting part in which an exhaust port is connected with the combustion chamber, a valve seat is provided. A head of a valve contacts the valve seat.
As a valve seat provided in a cylinder head as stated above, there is known a seat that is formed by performing cladding on the above-mentioned connecting part of the cylinder head. For example, Japanese Patent Application Publication No. 2008-188648 (JP 2008-188648 A) discloses a valve seat cladded on the connecting part by feeding metal powder in the connecting part of the cylinder head while irradiating the connecting part with a laser beam. This type of valve seat has a high a degree of adhesion to the cylinder head, and heat transfer efficiency to the cylinder head is high. Therefore, it is possible to favorably restrain an increase in temperature of the valve seat and the head of the valve.
In the cylinder head disclosed in JP 2008-188648 A, the intake valve seat and the exhaust valve seat are both formed by cladding.